Kerodon

$\Newextarrow{\xRightarrow}{5,5}{0x21D2}$ $\newcommand\empty{}$
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$

Remark 4.7.3.22. Let $\kappa $ be a strongly inaccessible cardinal. Then $\kappa $ is regular: this follows immediately from the inequality $\mathrm{ecf}(\kappa ) \leq \mathrm{cf}(\kappa )$ of Remark 4.7.3.17.